// JScript 文件

 function createCode()   
 {    
   code = "";   
   var codeLength = 4;//验证码的长度   
   var checkCode = document.getElementById("checkCode");   
   var selectChar = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');//所有候选组成验证码的字符，当然也可以用中文的   
   //var selectChar = new Array(0,1,2,3,4,5,6,7,8,9);//所有候选组成验证码的字符，当然也可以用中文的   
        
   for(var i=0;i<codeLength;i++)   
   {             
       var charIndex = Math.floor(Math.random()*36);   
       code +=selectChar[charIndex];           
   }     
   if(checkCode)   
   {   
     checkCode.className="code";   
     checkCode.value = code;   
   }   
 }